Response-based resource management

ABSTRACT

Certain aspects of the present disclosure provide techniques for support response-based resource management. A UE may determine an uplink response to be transmitted in response to a downlink transmission by a first TRP participating in CoMP to the UE with a second TRP. The first UE may select which of the first TRP or the second TRP to transmit the uplink response to, based at least in part on the determined uplink response and may transmit the uplink response to the selected first or second TRP.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/259,206, filed Jan. 28, 2019 and which claims benefit of U.S.Provisional Patent Application No. 62/629,585 filed Feb. 12, 2018, whichare expressly incorporated herein by reference in their entireties.

FIELD OF DISCLOSURE

Aspects of the present disclosure relate to wireless communication, andmore particularly, to response-based resource management. As describedherein, aspects may be practiced in a factory environment and/or ultrareliable and low latency communications (URLLC).

DESCRIPTION OF RELATED ART

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power). Examples of such multiple-access technologies includeLong Term Evolution (LTE) systems, code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems.

In some examples, a wireless multiple-access communication system mayinclude a number of base stations, each simultaneously supportingcommunication for multiple communication devices, otherwise known asuser equipment (UEs). In LTE or LTE-A network, a set of one or more basestations may define an e NodeB (eNB). In other examples (e.g., in a nextgeneration or 5G network), a wireless multiple access communicationsystem may include a number of distributed units (DUs) (e.g., edge units(EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs),transmission reception points (TRPs), etc.) in communication with anumber of central units (CUs) (e.g., central nodes (CNs), access nodecontrollers (ANCs), etc.), where a set of one or more distributed units,in communication with a central unit, may define an access node (e.g., anew radio base station (NR BS), a new radio node-B (NR NB), a networknode, 5G NB, gNB, etc.). A base station or DU may communicate with a setof UEs on downlink channels (e.g., for transmissions from a base stationor to a UE) and uplink channels (e.g., for transmissions from a UE to aBS or DU).

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example of an emergingtelecommunication standard is new radio (NR), for example, 5G radioaccess. NR is a set of enhancements to the LTE mobile standardpromulgated by Third Generation Partnership Project (3GPP). It isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingOFDMA with a cyclic prefix (CP) on the downlink (DL) and on the uplink(UL) as well as support beamforming, multiple-input multiple-output(MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in NR technology.Preferably, these improvements should be applicable to othermulti-access technologies and the telecommunication standards thatemploy these technologies.

SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this disclosure provide advantages that include improvedcommunications between access points and stations in a wireless network.

Certain aspects of the present disclosure generally relate to methodsand apparatus for supporting response-based resource management.

Based, at least in part, on an UL response to be transmitted (e.g.,acknowledgment or negative acknowledgement), in response to a DLtransmission, a UE may determine which of a first or second TRP totransmit the response to. The first and second TRPs may be associatedwith different time-frequency resources, in an effort to minimizeinterference.

Based, at least in part, on a DL response to be transmitted (e.g.,acknowledgment or negative acknowledgement) in response to an ULtransmission by a UE, TRPs may determine which of the first or secondTRP will transmit the response to the UE. In some aspects, the first andsecond TRPs may be associated with different time-frequency resources,in an effort to minimize interference.

Certain aspects of the present disclosure provide a method for wirelesscommunication that may be performed, for example, by a UE. The methodgenerally includes determining an uplink response to be transmitted inresponse to a downlink transmission by a first transmit/receive point(TRP) participating in coordinated multipoint (CoMP) transmissions tothe UE with a second TRP, selecting which of the first TRP or the secondTRP to transmit the uplink response to, based at least in part on thedetermined uplink response, and transmitting the uplink response to theselected first or second TRP.

Certain aspects of the present disclosure provide a method for wirelesscommunication that may be performed, for example, by a first TRP. Themethod generally includes determining a negative acknowledgement (NACK)to be transmitted to a user equipment (UE) in response to an uplinktransmission by the UE, and transmitting, to a second TRP, an indicationof the NACK to be transmitted, wherein the first TRP participates incoordinated multipoint (CoMP) transmissions to the UE with the secondTRP.

Certain aspects of the present disclosure provide a method for wirelesscommunication that may be performed, for example, by a second TRP. Themethod generally includes receiving an indication of a negativeacknowledgment (NACK) to be transmitted to a user equipment (UE) inresponse to an uplink transmission from the UE to a first TRP, whereinthe second TRP participates in coordinated multipoint (CoMP)transmissions to the UE with the first TRP, and transmitting the NACK tothe UE based, at least in part, on the indication.

Certain aspects of the present disclosure provide an apparatus forwireless communication that may be performed, for example, by a UE. Theapparatus generally includes means for determining an uplink response tobe transmitted in response to a downlink transmission by a firsttransmit/receive point (TRP) participating in coordinated multipoint(CoMP) transmissions to the UE with a second TRP, means for selectingwhich of the first TRP or the second TRP to transmit the uplink responseto, based at least in part on the determined uplink response, and meansfor transmitting the uplink response to the selected first or secondTRP.

Certain aspects of the present disclosure provide an apparatus forwireless communication that may be performed, for example, by a firstTRP. The apparatus generally includes means for determining a negativeacknowledgement (NACK) to be transmitted to a user equipment (UE) inresponse to an uplink transmission by the UE, and means fortransmitting, to a second TRP, an indication of the NACK to betransmitted, wherein the first TRP participates in coordinatedmultipoint (CoMP) transmissions to the UE with the second TRP.

Certain aspects of the present disclosure provide an apparatus forwireless communication that may be performed, for example, by a secondTRP. The apparatus generally includes means for receiving an indicationof a negative acknowledgment (NACK) to be transmitted to a userequipment (UE) in response to an uplink transmission from the UE to afirst TRP, wherein the second TRP participates in coordinated multipoint(CoMP) transmissions to the UE with the first TRP, and means fortransmitting the NACK to the UE based, at least in part, on theindication.

Certain aspects of the present disclosure provide an apparatus forwireless communication that may be performed, for example, by a UE. Theapparatus includes at least one processor and a memory coupled to the atleast one processor. The at least one processor is configured todetermine an uplink response to be transmitted in response to a downlinktransmission by a first transmit/receive point (TRP) participating incoordinated multipoint (CoMP) transmissions to the UE with a second TRP,select which of the first TRP or the second TRP to transmit the uplinkresponse to, based at least in part on the determined uplink response,and transmit the uplink response to the selected first or second TRP.

Certain aspects of the present disclosure provide an apparatus forwireless communication that may be performed, for example, by a firstTRP. The apparatus includes at least one processor and a memory coupledto the at least one processor. The at least one processor is configuredto determine a negative acknowledgement (NACK) to be transmitted to auser equipment (UE) in response to an uplink transmission by the UE, andtransmit, to a second TRP, an indication of the NACK to be transmitted,wherein the first TRP participates in coordinated multipoint (CoMP)transmissions to the UE with the second TRP.

Certain aspects of the present disclosure provide an apparatus forwireless communication that may be performed, for example, by a secondTRP. The apparatus includes at least one processor and a memory coupledto the at least one processor. The at least one processor is configuredto receive an indication of a negative acknowledgment (NACK) to betransmitted to a user equipment (UE) in response to an uplinktransmission from the UE to a first TRP, wherein the second TRPparticipates in coordinated multipoint (CoMP) transmissions to the UEwith the first TRP, and transmit the NACK to the UE based, at least inpart, on the indication.

Certain aspects of the present disclosure provide a computer readablemedium for wireless communication by a UE comprising instructions storedthereon for determining an uplink response to be transmitted in responseto a downlink transmission by a first transmit/receive point (TRP)participating in coordinated multipoint (CoMP) transmissions to the UEwith a second TRP, selecting which of the first TRP or the second TRP totransmit the uplink response to, based at least in part on thedetermined uplink response, and transmitting the uplink response to theselected first or second TRP.

Certain aspects of the present disclosure provide a computer readablemedium for wireless communication that may be performed, for example, bya first TRP comprising instructions stored thereon for determining anegative acknowledgement (NACK) to be transmitted to a user equipment(UE) in response to an uplink transmission by the UE, and transmitting,to a second TRP, an indication of the NACK to be transmitted, whereinthe first TRP participates in coordinated multipoint (CoMP)transmissions to the UE with the second TRP.

Certain aspects of the present disclosure provide a computer readablemedium for wireless communication that may be performed, for example, bya second TRP comprising instructions stored thereon for receiving anindication of a negative acknowledgment (NACK) to be transmitted to auser equipment (UE) in response to an uplink transmission from the UE toa first TRP, wherein the second TRP participates in coordinatedmultipoint (CoMP) transmissions to the UE with the first TRP, andtransmitting the NACK to the UE based, at least in part, on theindication.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects.

FIG. 1 is a block diagram conceptually illustrating an exampletelecommunications system, in accordance with certain aspects of thepresent disclosure.

FIG. 2 is a block diagram illustrating an example logical architectureof a distributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 3 is a diagram illustrating an example physical architecture of adistributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 4 is a block diagram conceptually illustrating a design of anexample TRP and user equipment (UE), in accordance with certain aspectsof the present disclosure.

FIG. 5 is a diagram showing examples for implementing a communicationprotocol stack, in accordance with certain aspects of the presentdisclosure.

FIG. 6 illustrates an example of a frame format for a new radio (NR)system, in accordance with certain aspects of the present disclosure.

FIG. 7 illustrates an example of a wireless communication environment,in accordance with certain aspects of the present disclosure.

FIG. 8 illustrates example requirements associated with the examplecommunication environment illustrated in FIG. 7 .

FIG. 9 illustrates an example of CoMP clusters, in accordance withcertain aspects of the present disclosure.

FIG. 10 illustrates example operations performed by a UE, in accordancewith certain aspects of the present disclosure.

FIG. 11 illustrates an example UE, first TRP, and second TRP, inaccordance with certain aspects of the present disclosure.

FIG. 12 illustrates example operations performed by a first TRP, inaccordance with certain aspects of the present disclosure.

FIG. 13 illustrates example operations performed by a second TRP, inaccordance with certain aspects of the present disclosure.

FIG. 14 illustrates an example UE, first TRP, and second TRP, inaccordance with certain aspects of the present disclosure.

FIG. 15 illustrates a block diagram of a UE configured to performresponse-based resource management, according to aspects of the presentdisclosure.

FIG. 16 illustrates a block diagram of a TRP configured to performresponse-based resource management, according to aspects of the presentdisclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processingsystems, and computer readable mediums for new radio (NR) (new radioaccess technology or 5G technology).

NR may support various wireless communication services, such as Enhancedmobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz beyond),millimeter wave (mmW) targeting high carrier frequency (e.g., 60 GHz),massive MTC (mMTC) targeting non-backward compatible MTC techniques,and/or mission critical techniques targeting ultra reliable low latencycommunications (URLLC). These services may include latency andreliability requirements. These services may also have differenttransmission time intervals (TTI) to meet respective quality of service(QoS) requirements. In addition, these services may co-exist in the samesubframe.

Aspects of the present disclosure provide methods and apparatus forresponse-based resource management. Response-based resource managementprovides increased reliability for a response transmission (ACK/NACK),by taking into account channel conditions associated with the firsttransmission (or, depending on point of view, the first reception).Based on a response to be transmitted, a UE may determine which TRP totransmit the response to.

As an example, a first TRP may transmit a first downlink transmission toa UE. In response to the first DL, the UE may determine a NACK is to betransmitted. A NACK may imply that a poor channel exists between the UEand the first TRP. During poor channel conditions, or environments thathave stringent reliability requirements, the first TRP may not receivethe NACK. Factory automation setting or URLLC, for example, havestringent reliability requirements. According to aspects, the UE maytransmit the NACK to a second TRP. The first and second TRP mayparticipate in CoMP communication with the UE. The first and second TRPsmay be associated with different time-frequency resources. The secondTRP may transmit an indication of the NACK to the first TRP.

In another example, a UE may transmit an UL message to a first TRP.Based on a DL response to be transmitted in response to the ULtransmission, the first TRP may refrain from transmitting the response.Instead, the second TRP may transmit the response to the UE. If the DLresponse is a NACK, the channel between the UE and the first TRP may notmeet stringent reliability requirements. Therefore, the first TRP mayrefrain from sending the NACK. Instead, the second TRP may transmit theNACK. The first and second TRPs may participate in CoMP communicationwith the UE. The first and second TRPs may be associated with differenttime-frequency resources.

The methods and apparatus described herein increase reliability for areceiving a response by taking into account the channel conditions ofthe first transmission. This may be particularly important inenvironments having stringent latency and reliability requirements.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in some other examples. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim. The word “exemplary”is used herein to mean “serving as an example, instance, orillustration.” Any aspect described herein as “exemplary” is notnecessarily to be construed as preferred or advantageous over otheraspects.

The techniques described herein may be used for various wirelesscommunication networks such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA andother networks. The terms “network” and “system” are often usedinterchangeably. A CDMA network may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA network may implement aradio technology such as Global System for Mobile Communications (GSM).An OFDMA network may implement a radio technology such as NR (e.g. 5GRA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA andE-UTRA are part of Universal Mobile Telecommunication System (UMTS). NRis an emerging wireless communications technology under development inconjunction with the 5G Technology Forum (5GTF). 3GPP Long TermEvolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTS that useE-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). cdma2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thetechniques described herein may be used for the wireless networks andradio technologies mentioned above as well as other wireless networksand radio technologies. For clarity, while aspects may be describedherein using terminology commonly associated with 3G and/or 4G wirelesstechnologies, aspects of the present disclosure can be applied in othergeneration-based communication systems, such as 5G and later, includingNR technologies.

Example Wireless Communications System

FIG. 1 illustrates an example wireless network 100 in which aspects ofthe present disclosure may be performed. For example, the wirelessnetwork may be a new radio (NR) or 5G network. According to aspects ofthe present disclosure, UEs and TRPs may perform response-based resourcemanagement.

As will be described in more detail herein, a UE may be located in acoverage area of a CoMP cluster including two TRPs (for example 110 a,110 d). CoMP transmission by two TRPs is also illustrated in FIG. 9 .

A first TRP may transmit a DL transmission to the UE. If the UEdetermines an UL NACK is to be transmitted in response to the firsttransmission, the UE may transmit the NACK to the second TRP in thecluster.

A first TRP 110 a and a second TRP 100 d may participate in CoMPtransmission to the UE 120 a. The first TRP 110 a transmits a DLtransmission to the UE. The UE may determine an uplink response to betransmitted in response to the downlink transmission. The UE may selectwhich of the first TRP 110 a or the second TRP 110 d to transmit theuplink response to, based at least in part on the determined uplinkresponse. The UE may transmit the uplink response to the selected firstor second TRP.

As another example, the UE may transmit an UL message to the first TRP110 a. If the first TRP determines a DL NACK is to be transmitted inresponse to the first transmission, the first TRP 110 a may refrain fromtransmitting the NACK, since the channel condition between the UE andthe first TRP may be poor. Instead, the second TRP 110 d may transmitthe NACK.

The first TRP 110 a may determine a NACK to be transmitted to a UE 120 ain response to an uplink transmission by the UE. The first TRP 110 atransmits, to a second TRP 110 d, an indication of the NACK to betransmitted, wherein the first TRP participates in CoMP transmissions tothe UE with the second TRP. The indication may be transmitted via thenetwork controller 130 or directly between the first and second TRPs.

The second TRP 110 d may receive an indication of a NACK to betransmitted to a UE 120 a in response to an uplink transmission from theUE to a first TRP 110 a, wherein the second TRP participates in CoMPtransmissions to the UE with the first TRP. The second TRP 110 d maytransmit the NACK to the UE based, at least in part, on the indication.

UEs 120 may be configured to perform the operations 1000 and othermethods described herein and discussed in more detail belowresponse-based resource management. Base station (BS) 110 may comprise atransmission reception point (TRP), Node B (NB), 5G NB, access point(AP), new radio (NR) BS, etc.). The NR network 100 may include thecentral unit. The first TRP 110 a may perform the operations 1200 andother operations described herein and the second TRP 110 d may performthe operations 1300 and other operations described herein.

As an example, to aspects, the TRPs 110 a, 110 d and the UE 120 a mayeach include a resource manager module 140 a, 140 b, and 150,respectively. The resource manager may assist in response-based resourcemanagement. The resource manager may be a separate entity or may beincorporated within any one or more modules illustrated, for example inFIGS. 4, 15, and 16 . As an example, the resource manager may be part ofthe controller/processor 440, 480, processors 1504, 1604, processingsystem 1502, 1602 and/or the transceiver 432, 454, 1508, 1608. In theUE, the resource manager may determine to which TRP to transmit the ULresponse. In the TRPs, the resource manager may determine which one ofthe first or second TRP should transmit the DL response to the UE.

As illustrated in FIG. 1 , the wireless network 100 may include a numberof BSs 110 and other network entities. A BS may be a station thatcommunicates with UEs. Each BS 110 may provide communication coveragefor a particular geographic area. In 3GPP, the term “cell” can refer toa coverage area of a Node B and/or a Node B subsystem serving thiscoverage area, depending on the context in which the term is used. In NRsystems, the term “cell” and gNB, Node B, 5G NB, AP, NR BS, NR BS, orTRP may be interchangeable. In some examples, a cell may not necessarilybe stationary, and the geographic area of the cell may move according tothe location of a mobile base station. In some examples, the basestations may be interconnected to one another and/or to one or moreother base stations or network nodes (not shown) in the wireless network100 through various types of backhaul interfaces such as a directphysical connection, a virtual network, or the like using any suitabletransport network.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,etc. A frequency may also be referred to as a carrier, a frequencychannel, etc. Each frequency may support a single RAT in a givengeographic area in order to avoid interference between wireless networksof different RATs. In some cases, NR or 5G RAT networks may be deployed.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or other types of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a Closed Subscriber Group (CSG), UEs for users in the home,etc.). A BS for a macro cell may be referred to as a macro BS. A BS fora pico cell may be referred to as a pico BS. A BS for a femto cell maybe referred to as a femto BS or a home BS. In the example shown in FIG.1 , the BSs 110 a, 110 b and 110 c may be macro BSs for the macro cells102 a, 102 b and 102 c, respectively. The BS 110 x may be a pico BS fora pico cell 102 x. The BSs 110 y and 110 z may be femto BS for the femtocells 102 y and 102 z, respectively. A BS may support one or multiple(e.g., three) cells.

The wireless network 100 may also include relay stations. A relaystation is a station that receives a transmission of data and/or otherinformation from an upstream station (e.g., a BS or a UE) and sends atransmission of the data and/or other information to a downstreamstation (e.g., a UE or a BS). A relay station may also be a UE thatrelays transmissions for other UEs. In the example shown in FIG. 1 , arelay station 110 r may communicate with the BS 110 a and a UE 120 r inorder to facilitate communication between the BS 110 a and the UE 120 r.A relay station may also be referred to as a relay BS, a relay, etc.

The wireless network 100 may be a heterogeneous network that includesBSs of different types, e.g., macro BS, pico BS, femto BS, relays, etc.These different types of BSs may have different transmit power levels,different coverage areas, and different impact on interference in thewireless network 100. For example, macro BS may have a high transmitpower level (e.g., 20 Watts) whereas pico BS, femto BS, and relays mayhave a lower transmit power level (e.g., 1 Watt).

The wireless network 100 may support synchronous or asynchronousoperation. For synchronous operation, the BSs may have similar frametiming, and transmissions from different BSs may be approximatelyaligned in time. For asynchronous operation, the BSs may have differentframe timing, and transmissions from different BSs may not be aligned intime. The techniques described herein may be used for both synchronousand asynchronous operation.

A network controller 130 may couple to a set of BSs and providecoordination and control for these BSs. The network controller 130 maycommunicate with the BSs 110 via a backhaul. The BSs 110 may alsocommunicate with one another, e.g., directly or indirectly via wirelessor wireline backhaul.

The UEs 120 (e.g., 120 x, 120 y, etc.) may be dispersed throughout thewireless network 100, and each UE may be stationary or mobile. A UE mayalso be referred to as a mobile station, a terminal, an access terminal,a subscriber unit, a station, a Customer Premises Equipment (CPE), acellular phone, a smart phone, a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, a medical device or medical equipment, a biometricsensor/device, a wearable device such as a smart watch, smart clothing,smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, asmart bracelet, etc.), an entertainment device (e.g., a music device, avideo device, a satellite radio, etc.), a vehicular component or sensor,a smart meter/sensor, industrial manufacturing equipment, a globalpositioning system device, or any other suitable device that isconfigured to communicate via a wireless or wired medium. Some UEs maybe considered evolved or machine-type communication (MTC) devices orevolved MTC (eMTC) devices. MTC and eMTC UEs include, for example,robots, drones, remote devices, sensors, meters, monitors, locationtags, etc., that may communicate with a BS, another device (e.g., remotedevice), or some other entity. A wireless node may provide, for example,connectivity for or to a network (e.g., a wide area network such asInternet or a cellular network) via a wired or wireless communicationlink. Some UEs may be considered Internet-of-Things (IoT) devices.

In FIG. 1 , a solid line with double arrows indicates desiredtransmissions between a UE and a serving BS, which is a BS designated toserve the UE on the downlink and/or uplink. A dashed line with doublearrows indicates interfering transmissions between a UE and a BS.

Certain wireless networks (e.g., LTE) utilize orthogonal frequencydivision multiplexing (OFDM) on the downlink and single-carrierfrequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDMpartition the system bandwidth into multiple (K) orthogonal subcarriers,which are also commonly referred to as tones, bins, etc. Each subcarriermay be modulated with data. In general, modulation symbols are sent inthe frequency domain with OFDM and in the time domain with SC-FDM. Thespacing between adjacent subcarriers may be fixed, and the total numberof subcarriers (K) may be dependent on the system bandwidth. Forexample, the spacing of the subcarriers may be 15 kHz and the minimumresource allocation (called a ‘resource block’) may be 12 subcarriers(or 180 kHz). Consequently, the nominal FFT size may be equal to 128,256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10 or 20megahertz (MHz), respectively. The system bandwidth may also bepartitioned into subbands. For example, a subband may cover 1.8 MHz(i.e., 6 resource blocks), and there may be 1, 2, 4, 8 or 16 subbandsfor system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively.

While aspects of the examples described herein may be associated withLTE technologies, aspects of the present disclosure may be applicablewith other wireless communications systems, such as NR.

NR may utilize OFDM with a CP on the uplink and downlink and includesupport for half-duplex operation using TDD. A single component carrierbandwidth of 100 MHz may be supported. NR resource blocks may span 12sub-carriers with a subcarrier bandwidth of 75 kHz over a 0.1 msduration. Each radio frame may consist of 50 subframes with a length of10 ms. Consequently, each subframe may have a length of 0.2 ms. Eachsubframe may indicate a link direction (i.e., DL or UL) for datatransmission and the link direction for each subframe may be dynamicallyswitched. Each subframe may include DL/UL data as well as DL/UL controldata. UL and DL subframes for NR may be as described in more detailbelow with respect to FIGS. 6 and 7 . Beamforming may be supported andbeam direction may be dynamically configured. MIMO transmissions withprecoding may also be supported. MIMO configurations in the DL maysupport up to 8 transmit antennas with multi-layer DL transmissions upto 8 streams and up to 2 streams per UE. Multi-layer transmissions withup to 2 streams per UE may be supported. Aggregation of multiple cellsmay be supported with up to 8 serving cells. Alternatively, NR maysupport a different air interface, other than an OFDM-based. NR networksmay include entities such CUs and/or DUs.

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. Within the present disclosure, as discussed further below,the scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more subordinateentities. That is, for scheduled communication, subordinate entitiesutilize resources allocated by the scheduling entity. Base stations arenot the only entities that may function as a scheduling entity. That is,in some examples, a UE may function as a scheduling entity, schedulingresources for one or more subordinate entities (e.g., one or more otherUEs). In this example, the UE is functioning as a scheduling entity, andother UEs utilize resources scheduled by the UE for wirelesscommunication. A UE may function as a scheduling entity in apeer-to-peer (P2P) network, and/or in a mesh network. In a mesh networkexample, UEs may optionally communicate directly with one another inaddition to communicating with the scheduling entity.

Thus, in a wireless communication network with a scheduled access totime—frequency resources and having a cellular configuration, a P2Pconfiguration, and a mesh configuration, a scheduling entity and one ormore subordinate entities may communicate utilizing the scheduledresources.

As noted above, a RAN may include a CU and one or more DUs. A NR BS(e.g., gNB, 5G Node B, Node B, TRP, access point (AP)) may correspond toone or multiple BSs. NR cells can be configured as access cell (ACells)or data only cells (DCells). For example, the RAN (e.g., a central unitor distributed unit) can configure the cells. DCells may be cells usedfor carrier aggregation or dual connectivity, but not used for initialaccess, cell selection/reselection, or handover. In some cases DCellsmay not transmit synchronization signals—in some case cases DCells maytransmit SS. NR BSs may transmit downlink signals to UEs indicating thecell type. Based on the cell type indication, the UE may communicatewith the NR BS. For example, the UE may determine NR BSs to consider forcell selection, access, handover, and/or measurement based on theindicated cell type.

FIG. 2 illustrates an example logical architecture of a distributed RAN200, which may be implemented in the wireless communication systemillustrated in FIG. 1 . A 5G access node 206 may include an access nodecontroller (ANC) 202. The ANC may be a central unit (CU) of thedistributed RAN 200. The backhaul interface to the next generation corenetwork (NG-CN) 204 may terminate at the ANC. The backhaul interface toneighboring next generation access nodes (NG-ANs) may terminate at theANC. The ANC may include one or more TRPs 208 (which may also bereferred to as BSs, NR BSs, Node Bs, 5G NBs, APs, or some other term).As described above, a TRP may be used interchangeably with “cell.”

The TRPs 208 may be a DU. The TRPs may be connected to one ANC (ANC 202)or more than one ANC (not illustrated). For example, for RAN sharing,radio as a service (RaaS), and service specific deployments, the TRP maybe connected to more than one ANC. A TRP may include one or more antennaports. The TRPs may be configured to individually (e.g., dynamicselection) or jointly (e.g., joint transmission) serve traffic to a UE.

The local architecture 200 may be used to illustrate fronthauldefinition. The architecture may be defined that support fronthaulingsolutions across different deployment types. For example, thearchitecture may be based on transmit network capabilities (e.g.,bandwidth, latency, and/or jitter).

The architecture may share features and/or components with LTE.According to aspects, the next generation AN (NG-AN) 210 may supportdual connectivity with NR. The NG-AN may share a common fronthaul forLTE and NR.

The architecture may enable cooperation between and among TRPs 208. Forexample, cooperation may be present within a TRP and/or across TRPs viathe ANC 202. According to aspects, no inter-TRP interface may beneeded/present.

According to aspects, a dynamic configuration of split logical functionsmay be present within the architecture 200. As will be described in moredetail with reference to FIG. 5 , the Radio Resource Control (RRC)layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control(RLC) layer, Medium Access Control (MAC) layer, and a Physical (PHY)layers may be adaptably placed at the DU or CU (e.g., TRP or ANC,respectively). According to certain aspects, a BS may include a centralunit (CU) (e.g., ANC 202) and/or one or more distributed units (e.g.,one or more TRPs 208).

FIG. 3 illustrates an example physical architecture of a distributed RAN300, according to aspects of the present disclosure. A centralized corenetwork unit (C-CU) 302 may host core network functions. The C-CU may becentrally deployed. C-CU functionality may be offloaded (e.g., toadvanced wireless services (AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 304 may host one or more ANC functions.Optionally, the C-RU may host core network functions locally. The C-RUmay have distributed deployment. The C-RU may be closer to the networkedge.

A DU 306 may host one or more TRPs (edge node (EN), an edge unit (EU), aradio head (RH), a smart radio head (SRH), or the like). The DU may belocated at edges of the network with radio frequency (RF) functionality.

FIG. 4 illustrates example components of the BS 110 and UE 120illustrated in FIG. 1 , which may be used to implement aspects of thepresent disclosure. As described above, the BS may include a TRP. One ormore components of the BS 110 and UE 120 may be used to practice aspectsof the present disclosure. For example, antennas 452, Tx/Rx 454,processors 458, 464, 466, and/or controller/processor 480 of the UE 120and/or antennas 434, Tx/Rx 432, processors 420, 430, 438, and/orcontroller/processor 440 of the BS 110 may be used to perform theoperations described herein and illustrated with reference to FIGS. 9-14.

As described above, the BS and the UE may include a resource manager490, 495, respectively. According to an example, the resource managermay be configured assist in response-based resource management. Whilethe resource manager is illustrated as a separate entity in FIG. 4 ,according to certain aspects, the resource manager may be incorporatedin one or more other modules at the BS and UE. As an example, theresource manager module may be part of the controller/processor and/orthe transceiver.

FIG. 4 shows a block diagram of a design of a BS 110 and a UE 120, whichmay be one of the BSs and one of the UEs in FIG. 1 . For a restrictedassociation scenario, the base station 110 may be the macro BS 110 c inFIG. 1 , and the UE 120 may be the UE 120 y. The base station 110 mayalso be a base station of some other type. The base station 110 may beequipped with antennas 434 a through 434 t, and the UE 120 may beequipped with antennas 452 a through 452 r.

At the base station 110, a transmit processor 420 may receive data froma data source 412 and control information from a controller/processor440. The control information may be for the Physical Broadcast Channel(PBCH), Physical Control Format Indicator Channel (PCFICH), PhysicalHybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel(PDCCH), etc. The data may be for the Physical Downlink Shared Channel(PDSCH), etc. The processor 420 may process (e.g., encode and symbolmap) the data and control information to obtain data symbols and controlsymbols, respectively. The processor 420 may also generate referencesymbols, e.g., for the PSS, SSS, and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 430 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODs) 432 a through 432t. Each modulator 432 may process a respective output symbol stream(e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator432 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal.Downlink signals from modulators 432 a through 432 t may be transmittedvia the antennas 434 a through 434 t, respectively.

At the UE 120, the antennas 452 a through 452 r may receive the downlinksignals from the base station 110 and may provide received signals tothe demodulators (DEMODs) 454 a through 454 r, respectively. Eachdemodulator 454 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 454 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 456 may obtainreceived symbols from all the demodulators 454 a through 454 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 458 may process (e.g., demodulate,deinterleave, and decode) the detected symbols, provide decoded data forthe UE 120 to a data sink 460, and provide decoded control informationto a controller/processor 480.

On the uplink, at the UE 120, a transmit processor 464 may receive andprocess data (e.g., for the Physical Uplink Shared Channel (PUSCH)) froma data source 462 and control information (e.g., for the Physical UplinkControl Channel (PUCCH) from the controller/processor 480. The transmitprocessor 464 may also generate reference symbols for a referencesignal. The symbols from the transmit processor 464 may be precoded by aTX MIMO processor 466 if applicable, further processed by thedemodulators 454 a through 454 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 110. At the BS 110, the uplink signalsfrom the UE 120 may be received by the antennas 434, processed by themodulators 432, detected by a MIMO detector 436 if applicable, andfurther processed by a receive processor 438 to obtain decoded data andcontrol information sent by the UE 120. The receive processor 438 mayprovide the decoded data to a data sink 439 and the decoded controlinformation to the controller/processor 440.

The controllers/processors 440 and 480 may direct the operation at thebase station 110 and the UE 120, respectively. The processor 440 and/orother processors and modules at the base station 110 may perform ordirect, e.g., the execution of the functional blocks illustrated inFIGS. 12 and 13 , and/or other processes for the techniques describedherein. The processor 480 and/or other processors and modules at the UE120 may also perform or direct, e.g., the execution of the functionalblocks illustrated in FIG. 10 , and/or other processes for thetechniques described herein. The memories 442 and 482 may store data andprogram codes for the BS 110 and the UE 120, respectively. A scheduler444 may schedule UEs for data transmission on the downlink and/oruplink.

FIG. 5 illustrates a diagram 500 showing examples for implementing acommunications protocol stack, according to aspects of the presentdisclosure. The illustrated communications protocol stacks may beimplemented by devices operating in a in a 5G system (e.g., a systemthat supports uplink-based mobility). Diagram 500 illustrates acommunications protocol stack including a Radio Resource Control (RRC)layer 510, a Packet Data Convergence Protocol (PDCP) layer 515, a RadioLink Control (RLC) layer 520, a Medium Access Control (MAC) layer 525,and a Physical (PHY) layer 530. In various examples the layers of aprotocol stack may be implemented as separate modules of software,portions of a processor or ASIC, portions of non-collocated devicesconnected by a communications link, or various combinations thereof.Collocated and non-collocated implementations may be used, for example,in a protocol stack for a network access device (e.g., ANs, CUs, and/orDUs) or a UE.

A first option 505-a shows a split implementation of a protocol stack,in which implementation of the protocol stack is split between acentralized network access device (e.g., an ANC 202 in FIG. 2 ) anddistributed network access device (e.g., DU 208 in FIG. 2 ). In thefirst option 505-a, an RRC layer 510 and a PDCP layer 515 may beimplemented by the CU, and an RLC layer 520, a MAC layer 525, and a PHYlayer 530 may be implemented by the DU. In various examples the CU andthe DU may be collocated or non-collocated. The first option 505-a maybe useful in a macro cell, micro cell, or pico cell deployment.

A second option 505-b shows a unified implementation of a protocolstack, in which the protocol stack is implemented in a single networkaccess device (e.g., access node (AN), new radio base station (NR BS), anew radio Node-B (NR NB), a network node (NN), or the like). In thesecond option, the RRC layer 510, the PDCP layer 515, the RLC layer 520,the MAC layer 525, and the PHY layer 530 may each be implemented by theAN. The second option 505-b may be useful in a femto cell deployment.

Regardless of whether a network access device implements part or all ofa protocol stack, a UE may implement an entire protocol stack (e.g., theRRC layer 510, the PDCP layer 515, the RLC layer 520, the MAC layer 525,and the PHY layer 530) as shown at 505-c.

FIG. 6 is a diagram showing an example of a frame format 600 for NR. Thetransmission timeline for each of the downlink and uplink may bepartitioned into units of radio frames. Each radio frame may have apredetermined duration (e.g., 10 ms) and may be partitioned into 10subframes, each of 1 ms, with indices of 0 through 9. Each subframe mayinclude a variable number of slots depending on the subcarrier spacing.Each slot may include a variable number of symbol periods (e.g., 7 or 14symbols) depending on the subcarrier spacing. The symbol periods in eachslot may be assigned indices. A mini-slot is a subslot structure (e.g.,2, 3, or 4 symbols).

Each symbol in a slot may indicate a link direction (e.g., DL, UL, orflexible) for data transmission and the link direction for each subframemay be dynamically switched. The link directions may be based on theslot format. Each slot may include DL/UL data as well as DL/UL controlinformation.

In NR, a synchronization signal (SS) block is transmitted. The SS blockincludes a PSS, a SSS, and a two symbol PBCH. The SS block can betransmitted in a fixed slot location, such as the symbols 0-3 as shownin FIG. 6 . The PSS and SSS may be used by UEs for cell search andacquisition. The PSS may provide half-frame timing, the SS may providethe CP length and frame timing. The PSS and SSS may provide the cellidentity. The PBCH carries some basic system information, such asdownlink system bandwidth, timing information within radio frame, SSburst set periodicity, system frame number, etc. The SS blocks may beorganized into SS bursts to support beam sweeping. Further systeminformation such as, remaining minimum system information (RMSI), systeminformation blocks (SIBs), other system information (OSI) can betransmitted on a physical downlink shared channel (PDSCH) in certainsubframes.

In some circumstances, two or more subordinate entities (e.g., UEs) maycommunicate with each other using sidelink signals. Real-worldapplications of such sidelink communications may include public safety,proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V)communications, Internet of Everything (IoE) communications, IoTcommunications, mission-critical mesh, and/or various other suitableapplications. Generally, a sidelink signal may refer to a signalcommunicated from one subordinate entity (e.g., UE1) to anothersubordinate entity (e.g., UE2) without relaying that communicationthrough the scheduling entity (e.g., UE or BS), even though thescheduling entity may be utilized for scheduling and/or controlpurposes. In some examples, the sidelink signals may be communicatedusing a licensed spectrum (unlike wireless local area networks, whichtypically use an unlicensed spectrum).

A UE may operate in various radio resource configurations, including aconfiguration associated with transmitting pilots using a dedicated setof resources (e.g., a radio resource control (RRC) dedicated state,etc.) or a configuration associated with transmitting pilots using acommon set of resources (e.g., an RRC common state, etc.). Whenoperating in the RRC dedicated state, the UE may select a dedicated setof resources for transmitting a pilot signal to a network. Whenoperating in the RRC common state, the UE may select a common set ofresources for transmitting a pilot signal to the network. In eithercase, a pilot signal transmitted by the UE may be received by one ormore network access devices, such as an AN, or a DU, or portionsthereof. Each receiving network access device may be configured toreceive and measure pilot signals transmitted on the common set ofresources, and also receive and measure pilot signals transmitted ondedicated sets of resources allocated to the UEs for which the networkaccess device is a member of a monitoring set of network access devicesfor the UE. One or more of the receiving network access devices, or a CUto which receiving network access device(s) transmit the measurements ofthe pilot signals, may use the measurements to identify serving cellsfor the UEs, or to initiate a change of serving cell for one or more ofthe UEs.

Example Response-Based Resource Management

In an example factory automation scenario, multiple levels ofconnectivity exist. FIG. 7 illustrates an example factory automationscenario 700, in accordance with certain aspects of the presentdisclosure. Sensors and actuators (S/A) 702 occupy the lowest level.Examples of S/A include rotary motor devices, linear servo, and positionsensors. The S/A 702 are controller by Programmable Logic Controllers(PLC) 704. The PLCs include custom hardware which issue a series ofcommands and receive sensor input in real time. As an example, the PLCissues a motion command and receives position inputs in real-time. ThePLCs 704 are interconnected and coordinate with other PLCs. The PLCs 704are also interfaced to Human Machine Interfaces (HMI) 706. Example HMIsinclude tablets, panels, and wearables. HMIs 706 provide machine controlat the factory floor (e.g., start/stop), change modes (e.g., from“widget1” to “widget2”), and provide augmented reality/virtual reality(AR/VR) interfaces. A Management System 708, which may be running on anindustrial PC, provides overall software and security management, flowmanagement, and long-term key performance indicators (KPI) monitoring.

FIG. 8 illustrates example requirements associated with factoryautomation scenarios, such as the environment illustrated in FIG. 7 . Inan example, the latency requirement is particularly stringent ascompared to traditional wireless networks. As an example, round triptime (RTT) between the PLC 704 and S/A 702 may be approximately 0.5 msto 10 ms. URLLC also targets a RTT of 0.5 to 10 ms. The reliabilityrequirement may also be stringent. In an example, the packet error rate(PER) target may be 10⁻⁶. In certain scenarios, the PER may be asstringent at 10⁻⁹. In the factory automation scenarios, the packet sizestend to be small (e.g., 40-256 bytes) and the range of communicationbetween the S/As and PLCs may be around 100 meters. While aspects of thepresent disclosure address the URLLC and factory deployment scenarios,they may be used in any wireless communication environment.

CoMP is further refined in NR (5G). A first type of CoMP is CoordinatedScheduling/Coordinated Beamforming (CS/CB), where multiple TRPscoordinate to share channel state information (CSI) for multiple UEs. InCS/CB, data packets are transmitted from only one TRP. If a UE is likelyto experience excess interference from a neighboring TRP, theneighboring TRP may either not schedule a transmission that may causeinterference at the UE or the neighboring TRP may perform beamformingaway from the UE, so as to reduce interference experienced by the UE.

A second type of CoMP is Joint Transmission (JT). In JT, multiple TRPssimultaneously transmit the same data with appropriate beamformingweights. As the name implies, multiple TRPs are actively participatingby transmitting to the UE.

Dynamic Point Selection (DPS) is a specific form of JT. Transmission ofbeamformed data for a given UE is performed by a single TRP at each timeinstance. The single TRP that is transmitting at any given time may bedynamically switched on a per-slot or per-subframe basis. DPS providesdiversity because there are multiple transmissions involved for the samedata packet.

In LTE and NR, one goal is to improve capacity and achieve a higher rateon average. Aspects of the present disclosure address a goal of higherreliability in a CoMP scenario. As described with reference to FIG. 8 ,in the factory scenario and for URLLC, a key characteristic is the PERtarget is as low as a probability of 10⁻⁶ or even 10⁻⁹. To achievehigher reliability, resource management across different transmissionsand different TRPs for data and for control messaging including ACK/NACKfeedback may be performed as described herein. Resource management mayhelp ensure high reliability for data and control transmissions. Themethod and apparatus described herein address ACK/NACK transmissions andre-transmission resource allocation across TRPs to achieve highreliability.

FIG. 9 illustrates an example of three CoMP clusters in a factoryenvironment 900, according to aspects of the present disclosure.Multiple cells may exist in a factory environment. A cell may refer toone or more PLCs controlling one or more S/As in the PLC's local cell.Different cells are served by multiple TRPs (e.g., PLCs). Therefore,each UE (e.g., S/A) may be in a coverage area of a cluster of TRPs. Thecluster of TRPs may be a combination or subset of TRPs that are close byor in the vicinity of the UE such that the TRPs may participate in CoMPtransmissions with the UE.

CoMP clusters have TRPs as well as time-frequency resources. Theresource allocation may be semi-static and employ spatial reuse, whereinthe same resources are not used in adjacent or neighboring sectors forinterference management. Examples of time-frequency resources includephysical resource blocks.

In FIG. 9 , Cluster A, Cluster B, and Cluster C co-exist spatially on alarge factory floor. Resources are pre-assigned to the TRPs of eachcluster. TRP 901 in Cluster A uses different time-frequency resourcesthan TRP 902 in Cluster A. TRP 903 in Cluster B, which is adjacent toTRP 902 in Cluster A, uses different time-frequency resources than TRP902. Based on the geometry of the TRP locations, TRPs 901 and 903 mayuse the same (or similar) time-frequency resources. Following thislogic, TRPs 901, 903, and 905 use a same or similar set oftime-frequency resources, such as PRB1 and TRPs 902, 904, and 906 use asame or similar set of time-frequency resources, such as PRB2. Theresources used by TRP 901, 903, and 905 are different than the resourcesuses by TRP 902, 904, and 906 to manage interference across TRPs.

The response-based resource management is based, at least in part, on afirst transmission. The first transmission (DL or UL) targets a specificblock error ratio (BLER). The BLER may be aggressive, thereforeresponse-resources may be well utilized if the channel between the TRPand UE is good. However, if the channel between the TRP and the UE isnot good, then further communication using initial channel should belimited in an effort to meet stringent latency requirements. A higherreliability for subsequent transmissions is achieved by taking intoaccount the channel conditions associated with the initial transmission.

As described with reference to FIG. 9 , in an effort to address the useof reliably transmitting and receiving information, neighboring TRPs ina multi-TRP scenario are allocated orthogonal time/frequency resourcesto minimize interference and increase PUCCH readability. As described inmore detail herein, although a UE usually sends PUCCH on resource 1 toTRP1, if the UE knows its channel with TRP1 is poor, then UE sends thePUCCH on resource 2, which is monitored by TRP2. In this example,resource 2 may be known as a supplementary resource.

FIG. 10 illustrates example operations 1000 that may be performed by aUE. The UE may be UE 120 a which may include one or more modules of UE120 illustrated in FIG. 4 . According to aspects the UE may be the UE1500 illustrated in FIG. 15 including one or more components configuredto perform the operations described herein.

At 1002, the UE may determine an uplink response to be transmitted inresponse to a downlink transmission by a first TRP participating in CoMPtransmissions to the UE with a second TRP. At 1004, the UE may selectwhich of the first TRP or the second TRP to transmit the uplink responseto, based at least in part on the determined uplink response. At 1006,the UE may transmit the uplink response to the selected first or secondTRP.

FIG. 11 illustrates an example UE 120 a, first TRP 110 a, and second TRP110 d. The first TRP 110 a transmits a first DL transmission to the UE.

Traffic in the factory environment is periodic. Accordingly, the initialtransmission is based on semi-persistent scheduling (SPS). Because ofSPS transmissions, the UE is not required to decode a PDCCH.

If the UE determines an ACK is to be transmitted in response to the DLtransmission from the first TRP 11 a, the UE transmits to ACK using theresources assigned to the first TRP 110 a.

If the UE is not able to decode its scheduled transmission, it maydetermine the uplink response to be transmitted is a NACK. According toaspects, the UE may determine that it did not receive or properly decodethe first transmission from the first TRP. Accordingly, the UE maydetermine a NACK is to be transmitted. If the UE determines a NACK is tobe transmitted, it transmits the NACK to the second TRP 110 d, using theresources assigned to the second TRP.

Because the UE did not successfully decode the DL transmission from thefirst TRP 110 a, the channel between the first TRP 110 a and the UE 120a may fall below a signal quality threshold value. Therefore, the UEtransmits the NACK using the resources assigned to the second TRP in aneffort to ensure that the uplink response (e.g., the NACK) issuccessfully received by the network.

In one example, as illustrated in FIG. 11 , the robotic arm may blockthe DL transmission from the first TRP 110 a to the UE 120 a. Movementof the robotic arm may be slow relative to a slot duration. Therefore,the UE transmits the NACK to the second TRP 110 d. The first and secondTRPs may communicate via a controller (e.g., 130) and/or a backhaulconnection.

After the UE 120 a transmits the NACK to the second TRP 110 d using thetime-frequency resources assigned to the second TRP, the second TRP maytransmit a retransmission of a downlink control channel, such as aPDCCH, to the UE. Additionally, or alternatively, the second TRP mayretransmit the initial downlink transmission (that was transmitted bythe first TRP). Transmission of the downlink control channel or aretransmission of the initial downlink transmission by the second TRP,as opposed to the first TRP, provides higher reliability the UE willreceive the transmission.

FIG. 12 illustrates example operations 1200 that may be performed by afirst TRP. The first TRP may be TRP 110 a which may include one or moremodules of TRP 110 illustrated in FIG. 4 . According to aspects the TRPmay be the TRP 1600 illustrated in FIG. 16 including one or morecomponents configured to perform the operations described herein. Thefirst TRP and a second TRP may participate in CoMP communication to aUE.

At 1202, the first TRP may determine a NACK is to be transmitted to a UEin response to an uplink transmission by the UE. At 1204, the first TRPmay transmit, to a second TRP, an indication of the NACK to betransmitted, wherein the first TRP participates in CoMP transmissions tothe UE with the second TRP.

FIG. 13 illustrates example operations 1300 that may be performed by asecond TRP. The second TRP may be TRP 110 d which may include one ormore modules of TRP 110 illustrated in FIG. 4 . According to aspects theTRP may be the TRP 1602 illustrated in FIG. 16 including one or morecomponents configured to perform the operations described herein. Inaspects, the second TRP participates in CoMP communication.

At 1302, the second TRP may receive an indication of a NACK to betransmitted to a UE in response to an uplink transmission from the UE toa first TRP. The second TRP participates in CoMP transmissions to the UEwith the first TRP. At 1304, the second TRP may transmit the NACK to theUE based, at least in part, on the indication.

A first TRP receives an initial UL transmission from a UE. If an ACK isto be transmitted to the UE, the first TRP transmits the ACK usingresources assigned to the first TRP. However, if the first TRPdetermines that it did not correctly decode the UL transmission, the DLresponse (e.g., NACK) is transmitted by the second TRP. The first TRPrefrains from transmitting the NACK because the channel between thefirst TRP and the UE may be poor. The second TRP transmits the NACKusing resources assigned to the second TRP. Additionally, the second TRPmay transmit the PDCCH on the resources assigned to the second TRP. Inone example, the second TRP transmits a resource allocation for UE'sre-transmission. The resource allocation may be transmitted on a DLcontrol channel, such as a PDCCH on a resource belonging to the secondTRP.

FIG. 14 illustrates an example UE 120 a, first TRP 110 a, and second TRP110 d. The UE 120 a transmits an UL transmission to the first TRP 110 d.Based on whether the first TRP 110 a is able to decode the ULtransmission, one of the first or second TRPs 110 a, 110 d may transmitthe DL response. If the first TRP 110 a is able to decode the ULtransmission, it transmits the ACK to the UE using resources assigned tothe first TRP. If the first TRP 110 a is not able to decode the ULtransmission, the first TRP will not transmit the NACK, as the channelbetween the UE and the first TRP may be poor. The first TRP may indicateto the second TRP 110 d (via a network controller, or backhaul link) totransmit the NACK to the UE. The second TRP 110 d may transmit the NACK.

Thus, as described herein, based on whether an ACK or NACK is to betransmitted, a UE may determine which resources to use for transmission.Similarly, TRPs may determine the resources to be used for a DL responseto an initial transmission based on whether the response is an ACK or aNACK.

FIG. 15 illustrates a communications device 1500, such as a UE that mayinclude various components corresponding to means-plus-functioncomponents configured to perform the response-based resource management,described herein. The communications device 1500 includes a processingsystem 1502 coupled to a transceiver 1508. The transceiver 1508 isconfigured to transmit and receive signals for the communications device1500 via an antenna 1510, such as the various signal described hereinThe processing system 1502 may be configured to perform processingfunctions for the communications device 1500, including processingsignals received and/or to be transmitted by the communications device1500.

The processing system 1502 includes a processor 1504 coupled to acomputer-readable medium/memory 1512 via a bus 1506. In certain aspects,the computer-readable medium/memory 1512 is configured to storeinstructions that when executed by processor 1504, cause the processor1504 to perform the operations illustrated in FIG. 10 , or otheroperations for performing the various techniques discussed herein.

In certain aspects, the processing system 1502 further includes adetermining component 1514 for performing the determining operationsillustrated in FIG. 10 . Additionally, the processing system 1502includes a selecting component 1516 for performing the selectingoperation illustrated in FIG. 10 . The determining component 1514 andselecting component 1516 may be coupled to the processor 1504 via bus1506. In certain aspects, the determining component 1514 and theselecting component 1516 may be hardware circuits. In certain aspects,the determining component 1514 and the selecting component 1516 may besoftware components that are executed and run on processor 1502.

FIG. 16 illustrates a communications device 1600, such as a TRP that mayinclude various components corresponding to means-plus-functioncomponents configured to perform the response-based resource management,described herein. The communications device 1600 includes a processingsystem 1602 coupled to a transceiver 1608. The transceiver 1608 isconfigured to transmit and receive signals for the communications device1600 via an antenna 1610, such as the various signal described hereinThe processing system 1602 may be configured to perform processingfunctions for the communications device 1600, including processingsignals received and/or to be transmitted by the communications device1600.

The processing system 1602 includes a processor 1604 coupled to acomputer-readable medium/memory 1612 via a bus 1606. In certain aspects,the computer-readable medium/memory 1612 is configured to storeinstructions that when executed by processor 1604, cause the processor1604 to perform the operations illustrated in FIG. 12 or 13 , or otheroperations for performing the various techniques discussed herein.

In certain aspects, the processing system 1602 further includes adetermining component 1614 for performing the determining operationsillustrated in FIGS. 12 and/or 13 . The determining component 1614 maybe coupled to the processor 1604 via bus 1606. In certain aspects, thedetermining component 1614 may be hardware circuits. In certain aspects,the determining component 1614 may be software components that areexecuted and run on processor 1602.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. All structural andfunctional equivalents to the elements of the various aspects describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35U.S.C. § 112, sixth paragraph, unless the element is expressly recitedusing the phrase “means for” or, in the case of a method claim, theelement is recited using the phrase “step for.”

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components withsimilar numbering.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a userterminal 120 (see FIG. 1 ), a user interface (e.g., keypad, display,mouse, joystick, etc.) may also be connected to the bus. The bus mayalso link various other circuits such as timing sources, peripherals,voltage regulators, power management circuits, and the like, which arewell known in the art, and therefore, will not be described any further.The processor may be implemented with one or more general-purpose and/orspecial-purpose processors. Examples include microprocessors,microcontrollers, DSP processors, and other circuitry that can executesoftware. Those skilled in the art will recognize how best to implementthe described functionality for the processing system depending on theparticular application and the overall design constraints imposed on theoverall system.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, ROM (ReadOnly Memory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The machine-readable media may be embodied in acomputer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

Also, any connection is properly termed a computer-readable medium. Forexample, if the software is transmitted from a website, server, or otherremote source using a coaxial cable, fiber optic cable, twisted pair,digital subscriber line (DSL), or wireless technologies such as infrared(IR), radio, and microwave, then the coaxial cable, fiber optic cable,twisted pair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer-readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein. For example, instructions for perform the operations describedherein and illustrated in FIGS. 10, 12, and 13 .

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

The invention claimed is:
 1. A method for wireless communication by afirst transmit/receive point (TRP), comprising: determining a negativeacknowledgement (NACK) to be transmitted to a user equipment (UE) inresponse to an uplink transmission by the UE; and transmitting, to asecond TRP, an indication of the NACK to be transmitted, wherein thefirst TRP participates in coordinated multipoint (CoMP) transmissions tothe UE with the second TRP.
 2. The method of claim 1, wherein thetransmitting comprises: transmitting, to a controller configured tocommunicate with the first and second TRPs, an indication of the NACK.3. The method of claim 1, further comprising: refraining fromtransmitting the NACK in response to the uplink transmission.
 4. Themethod of claim 1, wherein a first set of time-frequency resources areallocated to the first TRP and a second set of time-frequency resourcesare allocated to the second TRP.
 5. The method of claim 1, wherein thefirst TRP communicates with the UE using ultra-reliable low latencycommunication (URLLC).
 6. A method for wireless communication by asecond transmit/receive point (TRP), comprising: receiving an indicationof a negative acknowledgment (NACK) to be transmitted to a userequipment (UE) in response to an uplink transmission from the UE to afirst TRP, wherein the second TRP participates in coordinated multipoint(CoMP) transmissions to the UE with the first TRP; and transmitting theNACK to the UE based, at least in part, on the indication.
 7. The methodof claim 6, wherein the receiving comprises: receiving the indication ofthe NACK to be transmitted from a controller configured to communicatewith the first and second TRPs.
 8. The method of claim 6, wherein afirst set of time-frequency resources are allocated to the first TRP anda second set of time-frequency resources are allocated to the secondTRP.
 9. The method of claim 6, further comprising: transmitting, to theUE, a downlink control channel transmission.
 10. The method of claim 6,further comprising: transmitting, to the UE, a resource allocation forretransmission of the uplink transmission by the UE.
 11. The method ofclaim 6, wherein the second TRP communicates with the UE usingultra-reliable low latency communication (URLLC).
 12. An apparatus forwireless communication by a first transmit/receive point (TRP),comprising: a memory; and one or more processors coupled to the memory,the memory and the one or more processors being configured to cause theapparatus to: determine a negative acknowledgement (NACK) to betransmitted to a user equipment (UE) in response to an uplinktransmission by the UE; and transmit, to a second TRP, an indication ofthe NACK to be transmitted, wherein the first TRP participates incoordinated multipoint (CoMP) transmissions to the UE with the secondTRP.
 13. The apparatus of claim 12, wherein the memory and the one ormore processors being configured to cause the apparatus to transmitcomprises the memory and the one or more processors being configured tocause the apparatus to: transmit, to a controller configured tocommunicate with the first and second TRPs, an indication of the NACK.14. The apparatus of claim 12, wherein the memory and the one or moreprocessors are further configured to cause the apparatus to: refrainfrom transmitting the NACK in response to the uplink transmission. 15.The apparatus of claim 12, wherein: a first set of time-frequencyresources are allocated to the first TRP; and a second set oftime-frequency resources are allocated to the second TRP.
 16. Theapparatus of claim 12, wherein the first TRP communicates with the UEusing ultra-reliable low latency communication (URLLC).